Synthesis of poly(naphthalenecarboxamide)s with low polydispersity by chain‐growth condensation polymerization

Abstract

Condensation polymerization of 6‐(N‐substituted‐amino)‐2‐naphthoic acid esters (1) was investigated as an extension of chain‐growth condensation polymerization (CGCP). Methyl 6‐(3,7‐dimethyloctylamino)‐2‐naphthoate (1b) was polymerized at −10 °C in the presence of phenyl 4‐methylbenzoate (2) as an initiator and lithium 1,1,1,3,3,3‐hexamethyldisilazide (LiHMDS) as a base. When the feed ratio [1a]0/[2]0 was 10 or 20, poly(naphthalenecarboxamide) with defined molecular weight and low polydispersity was obtained, together with a small amount of cyclic trimer. However, polymer was precipitated during polymerization under similar conditions in [1a]0/[2]0 = 34. To increase the solubility of the polymer, monomers 1c and 1d with a tri(ethylene glycol) (TEG) monomethyl ether side chain instead of the 3,7‐dimethyloctyl side chain were synthesized. Polymerization of the methyl ester monomer 1c did not proceed well, affording only oligomer and unreacted 1c, whereas polymerization of the phenyl ester monomer 1d afforded well‐defined poly(naphthalenecarboxamide) together with small amounts of cyclic oligomers in [1d]0/[2]0 = 10 and 29. The polymerization at high feed ratio ([1d]0/[2]0 = 32.6) was accompanied with self‐condensation to give polyamide with a lower molecular weight than the calculated value. Such undesirable self‐condensation would result from insufficient deactivation of the electrophilic ester moiety by the electron‐donating resonance effect of the amide anion. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Synthesis of partially fluorinated poly(arylene ether sulfone) multiblock copolymers bearing perfluorosulfonic functions

“…Consequently, a variety of synthesis strategies aiming at increasing the acidity of the ionic function or/and at improving the membrane morphology has been explored to optimize the conductivity of aromatic ionomers. Regarding the search for increased acidity, aromatic ionomers bearing aryl sulfonimide acid 16,17 or alkyl perfluoro alkyl sulfonic acid side chains [18][19][20][21][22][23][24][25][26] instead of aryl sulfonic acid were recently proposed. The poly(arylene ether)s containing pendant PFSA groups showed more phaseseparated morphology and higher proton conductivity than those of the poly(arylene ether)s with main chain grafted sulfonic acid groups.…”

Synthesis and proton conductivity of sulfonated, multi-phenylated poly(arylene ether)s

“…7 As a result, alternative PEM materials, particularly those based on sulfonated aromatic polymers, are under intense investigation. [8][9][10][11][12][13][14][15][16][17][18][19][20] A feature characteristic of these materials is that a high degree of sulfonation is required to achieve highly ion-conductive membranes, which results in a high water uptake (WU), 21,22 a commensurate loss of mechanical strength and inferior fuel cell performance compared to PFSA ionomers. 21,23 To realize the properties of PFSA ionomers, it appears hydrocarbon analogues must emulate the morphology of PFSAs, i.e., an appropriate proportion of hydrophilic and hydrophobic segments are required to form nanophase-separated proton channels.…”

A versatile living polymerization method for aromatic amides

“…The higher dispersities compared to the p-aminobenzoic acid derivatives (A) investigated before are attributed to the reduced solubility of the formed polymers (PC1-PC3 and PD1, Supplementary Table 3) in the polymerization solvent (DCM) as was previously reported. 38,39 It was previously shown that PD1 can form helical polymers in solutions. 37 Circular dichroism spectroscopy of PD1 in cyclohexane at 5°C confirmed the reported negative Cotton effect (Supplementary Fig.…”